Electric furnace



Nov. 13, 1928.

J. C. WOODSQN ELECTRIC FURNACE Filed Jan. 19, 1927 INVENTOR AT'RNY WiTNESSESZ WAZ&/z,

Patented Nov. 13, I 1928.

UNITED- STATES PATENT OFFICE.

JAMES C. WOODSON, OF MANSFIELD, OHIO, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF IENNSYLVANLA.

ELECTRIC FURNACE.

, Application filed January 19, 1927. Serial No. 162,013.

My invention relates to electric arc furnaces and has for its object the provision of means for regulating the consumption of current in such furnaces.

In practicing my invention, I provide a furnace wherein a plugality, of plural electrode heads are'simmetrically arranged on the top thereof; The electrodes in each head are of the repel arc type and are pivotally mounted and weighted to normally bring the ends thereof into engaging relation, the arrangement being such that upon the establishment of a circuit through said electrodes a magnetic field is formed which swings them apart to establish an arc therebetween. Are furnaces of this type are well-known in the art and are shown more particularly in U. S. Patent No. 1,352,- 541 to 'V on Schlegell issued Sept. 14, 1920.

The arrangement of the electrode heads is.

such that one electrode in each head is adjacent to a single electrode of each of the other heads, and selective means areprovided to weight these adjacent electrodes to' swing them in an opposite direction.

Switches and suitable reactances are provided in the circuits of all of the electrodes to selectively energize them.

In the accompanying drawings,

Fig. 1 is a plan view of an electric furnace embodying my invention;

Fig. 2 is a section in elevation, taken on the line II-II of Fig. 1; and

Fig. 3 is a diagrammatic showing of the circuit connections.

An electric arc furnace designated broadly as 1 and comprising a suitable refractory lining 2 and enclosing a furnace chamber 3, is provided with three electrode heads 4.

mounted in the top of the furnace and symmetrically arranged both peripherally and radially with respect to the center thereof. In each of these electrode heads there is mounted a heating unit comprising three electrodes such as a, b and 0. These electrodes are pivotally mounted by means of a collar 10 carrying depending knife edges 1.1. Sockets 13 are formed upon said collars 10 for receiving weight arms 14 upon which weights 12 are adjustably mounted to cause the lower ends of each set of electrodes, such as a, b and 0 to normally enage, all of which is disclosed in the Von Schlegell patent. In general the weights 1% are so located as to extend, away from the central axis of each electrode head. The electrodes a, b, and 0 of the three electrode heads respectively, are positioned adjacent to the center of the top of the furnace at equal distances therefrom. These three electrodes are provided with additional sockets 13 on the collars 10 thereof diametrically opposite to' the sockets 13 so that the weight members 12, 1 1 may be 'inserted therein to bias the ends of these electrodes in an opposite direction. Because of the position of these three electrodes adjacent to the center of the top of the furnace and symmetrically thereof into engaging relation.

Each of the electrodes a, a and a is electrically connected to phase a; of a three phase supply line as shown in Fig. 3, through 7 suitable switch means and reactances, as indicated at 16 in Fig. 3. Likewise electrodes 2), Z) and b and electrodes 0', c and 0' are connected to phases b and 0 respectively. In the normal operation of the devices with all of the switches closed, each of the electrode heads constitutes a separate heatall of the. switches are opened except those in the circuits of the three electrodes a, b

- and 0", weights and weight arms 1214 are then inserted into the sockets 13 of the respaced peripherally thereof, this movement brings the ends spective collarlO and causes these electrodes to swing into operating relation to form a separate heating element at the centerof the furnace;

Various modifications may be made inthe device embodying my invention without departing from the spirit and scope thereof, and I desire that only such limitations shall be placed thereon as are impo-ted by the prior art or are specifically set forth in the appended claims.

I claim as my invention:

1. In an electric arc furnace, aplurality of heating units comprising electrodes mounted in operative relation, means for electrically connecting said units for parallel operation, and means forming a separate heating unit composed of a single electrode from each of the first mentioned heating units.

2. In an electric furnace of the repel arc type, a plurality of groups of cooperating electrodes mounted in said furnace, means for electrically connecting said groups for parallel operation, means for selectively cutting out of circuit all but one of the electrodes of each group, and means for operating the remaining electrodes as a separate group.

3. In an electric arc furnace, a plurality of heating units mounted in the roof of said furnace, each of said units comprising a plurality of pivoted electrodes normally biased into cooperating relation, and selective means for biasing one electrode in each group into contacting relation with one electrode of each of the other groups to form a separate heating unit.

4. In an electric furnace, three heating units mounted in the roof of said furnace equidistant from the center thereof and from each other, said heating units each comprising pivotally mounted electrodes weighted to normally swing the ends thereof into cooperating relation, selective means to weight certain of said electrodes to swing in an opposite direction, said last named electrodes being so positioned that upon movement in said opposite direction the ends thereof are brought into cooperating relation to form a separate heating unit.

5. In an electric arc furnace, a plurality of heating units mounted in the roof thereof and comprising pivotally mounted electrodes JAMES C. WOODSON. 

